The comparison of different methods in hydrochemical classification using hierarchical clustering analysis

Hierarchical clustering analysis is one basic multivariate statistical instrument which is used in classifying research in multifarious fields widely. The most three common clustering methods are Single Linkage Method, Group Average Method and Ward Method in hierarchical clustering analysis. As it is about to confirm the sources, approaches and conditions of water leakage in BaYi tunnel, this article analyses the advantages, the disadvantages and the applicable conditions of these three methods taking BaYi tunnel as an example to hierarchical clustering analyse in hydrochemical classification. The results indicate that the Single Linkage Method is not capable dealing with complicated actual situations and the Ward Method is applicable in samples of narrow amount while the Group Average Method can be used competently in general conditions.